correct a order of refs and add line break

Signed-off-by: Alexei Karikov <karikov.alist.ru@gmail.com>

CONTRIBUTING.md

@@ -5,8 +5,8 @@
     - [Feature Requests](#feature-requests)
     - [Documentation Changes](#documentation-changes)
     - [Contributing Code](#contributing-code)
-  - [First pull request](#first-pull-request)
   - [Developer Certificate of Origin](#developer-certificate-of-origin)
+  - [First pull request](#first-pull-request)
   - [Changelog](#changelog)
   - [Review Process](#review-process)
 
@@ -128,6 +128,7 @@ Each commit must include a DCO which looks like this
 Signed-off-by: Jane Smith <jane.smith@email.com>
 ```
 You may type this line on your own when writing your commit messages. However, if your user.name and user.email are set in your git configs, you can use `-s` or `--signoff` to add the `Signed-off-by` line to the end of the commit message.
+
 Fill in your personal details as well as an email that is public on github:
 
 ```